/Engine/Plugins/Developer/Concert/ConcertMain/Source/Concert/Public/IConcertSession.h
Register a custom request handler for this session
template<typename RequestType, typename ResponseType, typename HandlerType> void RegisterCustomRequestHandler ( HandlerType * Handler, typename [TConcertRawSessionCustomRequestHandler](API\Plugins\Concert\TConcertRawSessionCustomRequestH-)< RequestType, ResponseType, HandlerType >::FFuncType Func )